The present invention relates to the manufacture of rods such as are useful for the manufacture of filter elements for smoking articles, and in particular, to filter rods having pelletized materials spaced at predetermined intervals therein.
Popular smoking articles such as cigarettes have a substantially cylindrical rod shaped structure and include a charge of smokable material such as shredded tobacco (e.g., cut filler) surrounded by a paper wrapper thereby forming a so-called "tobacco rod." It has become desirable to manufacture cigarettes having cylindrical filter elements aligned in an end-to-end relationship with the tobacco rod. Typically, filter elements are manufactured from fibrous materials such as cellulose acetate tow which is circumscribed by plug wrap. The filter element is attached to the tobacco rod using a circumscribing tipping material. The filter elements generally are provided from so called "filter rods."
Apparatus and methods for providing a cigarette filter rod containing a smoke modifying agent are proposed by Pryor in U.S. Pat. Nos. 4,549,875; 4,525,385 and 4,476,807. Another type of cigarette filter rod having a continuous flavored thread incorporated therein or wrapped in flavored tape is proposed by Bynre et al in U.S. Pat. No. 4,281,671. Still other apparatus and methods for manufacturing filter rods having particulate or granular smoke modifying material dispensed therein are proposed by Sexstone in U.S. Pat. Nos. 3,884,741; 3,884,200; 3,957,563 and 4,016,830.
It would be highly desirable to provide an apparatus and method for manufacturing cigarette filter rods having well controlled amounts of smoke modifying agent therein.